I share some notes that I jotted down from Douglas Fox, “The Brain, Reimagined: Physicists who have revived experiments from 50 years ago say nerve cells communicate with mechanical pulses, not electric ones,” Scientific American (April 2018): 60-67:
Curiously, although physicians have been administering general anesthesia for nearly two centuries now, and although they have discovered dozens of different but effective anesthetic compounds, nobody actually knows exactly how anesthesia works. We know that they all shut down body and brain functions in the same order — memory formation first, then pain sensation, then consciousness and, ultimately, breathing — across all animal species, from flies to humans. But nitrous oxide , ether, sevoflurane, and xenon are so very different in their molecular structure that it seems highly unlikely that they function in the same way in their common effects.
Thomas Heimburg, a physicist at the Niels Bohr Institute in Copenhagen who trained in quantum mechanics and biophysics at the Max Planck Institute for Biophysical Chemistry in Göttingen, Germany, believes that anesthetics change the mechanical properties of nerves. What difference would that make? Writing for Scientific American, Douglas Fox says that,
If that is true, it means that nerve cells, or neurons, throughout the body and brain are mechanical machines, not the electric circuits scientists have believed in for decades (62).
The mechanical components may have been overlooked because of an accident of history: 50 years ago off-the-shelf instruments could readily measure the tiny electric impulses in neurons but not the mechanical ones. Hardware limitations influenced which discoveries scientists made and which ideas entered mainstream scientific thought. (63)
In 1963, two British scientists, Alan Hodgkin and Andrew Huxley, won a Nobel Prize for work that established modern neurophysiology on the basis of the electrical model.
Some scientists, though — prominent among them Ichiji Tasaki of the National Institute of Health, who died in December 2008 after a fall at the age of ninety-eight, but who had worked seven days a week on such issues until into his nineties — challenged the Hodgkin/Huxley model. Tasaki encountered fierce personal opposition, though, from such luminaries as the prominent neuroscientist Kenneth Cole, also at the NIH, and his own shaky English hindered him, as well. Having begun his research in Tokyo during the isolation and economic wreckage of World War Two, Tasaki had been obliged to create his own unique lab equipment from stray components. This permitted him an idiosyncratic point of view, allowing him to see things that others did not.
Heimburg, though, came across Tasaki’s work while a doctoral student in the mid-1980s. He also went back to an old volume published by one Ernest Overton in 1901, entitled Studien über die Narkose (“Studies of Narcosis”) and to the work of the great German physicist Hermann von Helmholtz, a key figure in the development of thermodynamics in the mid-1800s. “I find it absolutely mandatory to read these old texts,” he says.
Says Scientific American‘s Douglas Fox:
The story of the mechanical neuron holds lessons for all of science about biases and accidents of history. It also could change our basic understanding of nerves, brains and intelligence. Scientists have struggled to explain such daunting feats as face recognition and conversation while relying on proteins in neurons that are electrically noisy and unreliable. Heimburg is showing how the mechanical waves may compensate for this noise. If his theory proves out, he could rewrite biology. Or he might just be wrong. (63)
There is definitely opposition to Heimburg, especially among some neurobiologists who think that, as primarily a physicist, he is ignoring the unique perspective of their field. As Douglas Fox says, there may be a Nobel Prize in the future. Or nothing.
The article was published two years ago this month, and I’m anything but a specialist in neuroscience. So, if anybody out there knows where things currently stand, I would be interested.
[Postscript: To those who obsessively scan these entries seeking evidence of plagiarism against me: These are, as I said above, notes from Douglas Fox, “The Brain, Reimagined: Physicists who have revived experiments from 50 years ago say nerve cells communicate with mechanical pulses, not electric ones,” Scientific American (April 2018): 60-67. They are notes from that text. I do not count them as my original creation. I do not count them as a publication of mine. They are notes, of the kind that I would, in previous days, have written onto an index card or into a notebook. I share them because I think that some might find them of interest, and also because using them as blog entries gives me an incentive to extract them from my readings. It’s plainly easier and faster to read and to mark passages than to copy out notes of those marked passages, but making double use of them (here currently, and as resource material for a planned future book) makes the task more agreeable to me.]